1. Field of the Invention
Embodiments of the present invention relates to the technical field of electrowetting display, and more particular, to an electrowetting array substrate and a display device.
2. Description of the Related Art
In our daily lives, demands for display devices progressively increase, and application products related to the display technique are continually developed. At present, conventional CRT displays have already been replaced by liquid crystal displays. However, such liquid crystal display, due to limitation of its principle, has defects, such as high energy consumption, slow response rate, small angle of visibility, low conversion ratio of color, low contrast and the like, and cannot meet progressively increasing demands of utilization. Accordingly, electrowetting technique is regarded as a new generation of display technique which will replace liquid crystal display technique in the future, owing to its merits of high black/white reflectivity, high conversion ratio of color, high contrast, large angle of visibility, fast response and the like.
Specifically, electrowetting display is a technique which utilizes “spreading-contracting” behaviors of a non-polar liquid on a hydrophobic dielectric layer to realize displaying effect. The operating principle for this is that when no voltage is applied to a pixel unit, the non-polar liquid spreads on a surface of the hydrophobic dielectric layer because an affinity of the non-polar liquid (e.g., black ink) with the hydrophobic dielectric layer is greater than that of a polar aqueous solution (e.g., aqueous electrolyte) with the hydrophobic dielectric layer, and when a voltage is applied to the pixel unit, charge distribution formed on the hydrophobic dielectric layer will enhance its affinity with the water, such that the non-polar liquid is forced to be pushed toward a corner of the pixel unit. Such “spreading-contracting” behavior of the non-polar liquid will be able to generate certain changes of reflection or refraction characteristic of the pixel unit to a light beam, so that different display states are presented.
However, in the electrowetting display device of the prior art, when a voltage is applied to the pixel unit, the non-polar liquid is usually pushed towards the corner of the pixel unit. On one hand, the longest movement distance of the non-polar liquid when converted from the spreading state to the state of being pushed towards the corner is a diagonal distance of the rectangular pixel unit. This will cause unnecessary time and energy consumption and will adversely influence increase of the response rate. On the other hand, after the non-polar liquid contracts to the corner of the pixel unit, the height of the non-polar liquid may be greater than that of a blocking wall. If the display device is strongly vibrated at this time, the non-polar liquid may accidentally enter into adjacent pixel units, causing degradation of displaying effect and even display fault.